Re: [PATCH v2 1/2] usb: misc: onboard_usb_hub: Don't create platform devices for DT nodes without 'vdd-supply'

Greg Kroah-Hartman
2022-12-22T05:50:17Z

On Thu, Dec 22, 2022 at 02:26:44AM +0000, Matthias Kaehlcke wrote:
> The primary task of the onboard_usb_hub driver is to control the
> power of an onboard USB hub. The driver gets the regulator from the
> device tree property "vdd-supply" of the hub's DT node. Some boards
> have device tree nodes for USB hubs supported by this driver, but
> don't specify a "vdd-supply". This is not an error per se, it just
> means that the onboard hub driver can't be used for these hubs, so
> don't create platform devices for such nodes.
>
> This change doesn't completely fix the reported regression. It
> should fix it for the RPi 3 B Plus and boards with similar hub
> configurations (compatible DT nodes without "vdd-supply"), boards
> that actually use the onboard hub driver could still be impacted
> by the race conditions discussed in that thread. Not creating the
> platform devices for nodes without "vdd-supply" is the right
> thing to do, independently from the race condition, which will
> be fixed in future patch.
>
> Fixes: 8bc063641ceb ("usb: misc: Add onboard_usb_hub driver")
> Link: https://lore.kernel.org/r/d04bcc45-3471-4417-b30b-5cf9880d785d@i2se.com/
> Reported-by: Stefan Wahren <stefan.wahren@i2se.com>
> Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
> ---
>
> Changes in v2:
> - don't create platform devices when "vdd-supply" is missing,
> rather than returning an error from _find_onboard_hub()
> - check for "vdd-supply" not "vdd" (Johan)
> - updated subject and commit message
> - added 'Link' tag (regzbot)
>
> drivers/usb/misc/onboard_usb_hub_pdevs.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree. Please read:
https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.